There are some places where you can expect wildfires. In California, fires burn from 50,000 to 500,000 acres of land every year. Some of the plants A have oily sap. They can survive the dry, hot summers, but if they catch fire they explode into flame. Grasses grow thick during the spring rains and then die. They dry into a thick layer of straw B, making a very hot fire.
Fires can start wherever there’s fuel to burn. Southern California has plenty of fuel and a hot, dry wind C between mid-September and late October. This wind, called the Santa Ana, passes over the inland desert, D, and rushes toward the ocean to the west. The Santa Ana wind fans the flames and makes fighting the fires nearly impossible.
In 1988, Wyoming’s Yellowstone National Park was burned by several fires at once. Lightning struck in two places. A worker dropped a lit cigarette in another place. On the worst day of fire, more than 600 square kilometers of forest burned. Clouds of smoke E rose into the atmosphere. Smoke blocked the sun and drifted far beyond the park.
Firefighters work hard to control fires like those in Yellowstone and California, F. But long before humans learned how to start or put out a fire, prairies and forests burned every year. Both kinds of land recovered, as they have in Yellowstone and in California.
1. that burns fast
2. many of which are caused by people
3. that blows every year
4. wherever lightning strikes
5. that looked like storm clouds
6. that live there
7. its air losing moisture and gaining heat
